Traditionally, heating boots have been attached between joists in houses by nailing 2.times.4's between the joists and nailing the boot to the 2.times.4's. The 2.times.4's must be cut to size and shape the appropriate distance apart in order to support the boot. This process is time consuming and requires a great deal of dexterity by the installer because the installer must hold the boot and the 2.times.4s while attempting to nail the 2.times.4s to the joists.
A number of references have utilized telescoping brackets to mount equipment between ceiling joists. For example, Hexdall U.S. Pat. No. 3,162,413, issued Dec. 22, 1964, discloses a bar hanger having slidable ends mounted thereon. U.S. Pat. No. 4,165,852, to Bowden, Jr., et al. issued Aug. 28, 1979, discloses an adjustable, lockable bar hanger having telescoping male and female members for hanging electrical ceiling boxes between a pair of joists. U.S. Pat. Nos. 3,518,421, Cogdill issued June 30, 1970; 3,163,386, Collins issued Dec. 29, 1964; and 2,965,342, Goldstone issued Dec. 20, 1960 all disclose the use of telescoping members.
The use of prongs to secure a bracket in place is also known. For example, the patents to Hexdall, Bowden, Collins, Goldstone, and Cogdill all disclose the use of prongs, retaining points, nailing points, or other mounting tangs.